"A young trainee was put in charge of measuring odor value (volatility vs intensity) for hundreds of pure molecules. The result of years of drudgery was a chart that you still see on office walls at Givaudan R&D (they bought Roure). It is supposed to be a secret, but photocopiers have put it in most perfumers’ hands."

Allegedly it's easy to get hold of it - not for me: this blurred picture is the best I could come up with!

If anybody has a copy of it please let me know, I'd love to have a look at it!